The Past, Present, and Potential Future of Phosphorus Management in the Florida Everglades - A Critical Review

Quinn Zacharias

Authors:  Quinn Zacharias, David Kaplan P.h.D.

Faculty Mentor: David Kaplan P.h.D.

College:  Herbert Wertheim College of Engineering


The Florida Everglades is a Wetland of International Significance and World Heritage Site. In the early twentieth century, the Everglades suffered significant decline in environmental health due to massive drainage projects, polluting farming practices and urban population growth. After a century of hydrologic degradation, Phosphorus (P) pollution became a primary challenge. In recent decades, strict water quality regulation has encouraged improved water and nutrient management, reducing P loading from some sources by up to 90%. However, these interventions have yet to consistently meet effluent regulations and Florida’s numeric total phosphorus (TP) criterion. Given the gap between policy expectations and the physical limitations of the system, it is useful to review the motivation for current P and water management approaches, where they have succeeded and failed, and how to adapt in the future. Specifically, this work reviews how and why specific P management goals and strategies were developed in the Everglades, including the scientific background for standards and policy development. Next, the review discusses current and future issues in P management, including ecological tradeoffs, developing technology, stakeholder equities, practical versus ideal P management, and the possibility of balancing multiple hydrologic and water quality goals.

Poster Pitch

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13 Responses
  1. Anays Hernandez

    Hi Quinn, great work! What are the negative implications of phosphorus and how can this be compared to any other environmental bacteria/hazards presented to the Everglades?

  2. Christopher Cuevas

    Great job on the poster, Quinn! I especially like the inclusion of a map in the lower left.

  3. quinn zacharias

    Hi Anays, phosphorus is a mineral that boosts plant and algae growth. It is naturally found in soils and waterways, but it is used in lawn and agricultural fertilizers. When too much of it enters the environment, the ecosystem responds and the natural composition of plants and animals changes and becomes impaired. The goal of the Everglades restoration has been to restore the everglades to a natural state. So far, the everglades has experienced phosphorus levels 20 times higher than the natural state. Sensitive habitat for many endangered animals in the everglades has been threatened by ecological degradation from this pollutant.

    There are other pollutant issues the Everglades are dealing with such as mercury. However, mercury is found in orders of magnitude less and its impacts have not been as profound as phosphorus. You might not want to eat the fish in the everglades if mercury is too high, but if phosphorus is too high, every niche at every trophic level in the ecosystem is impacted.

  4. Lars Bjorndal

    Hi Quinn,
    Really good poster and video. I do not really know what Phosphorus does in the environment, so what is the current effect of the phosphorus on the Everglades?

    1. quinn zacharias

      Hi lars, when to much phosphorus enters the environment, it acts as a stimulant for plants, algae and microorganisms. The problem is that it can accelerates the growth and reproduction of the wrong types organisms. It can throw the entire ecosystem off balance and collapse the system. In the Everglades, it impairs the natural ecosystem that many endangered animals rely on.

  5. Macartney Ewing

    Hi Quinn! Great poster and very informative. I had no idea what a large impact phosphorus has on our Florida Everglades, although I was already aware of how phosphorus is negatively affecting the oceans by causing increased algae blooms. Great job!

    1. quinn zacharias

      The algae blooms you see in the ocean are caused by the same mechanism, eutrophication. This word is latin for “enriching with energy”. Phosphorus fertilizes ecosystems and increases their production and reproduction. However, the wrong kinds of organisms can reproduce to fast and grow to large that it throws the ecosystem balance off and alters/crashes the system,

  6. Jennifer Sonaly Vale

    Hi Quinn,

    Great job! Congrats on how far you’ve come! I very much enjoyed your video, I think you did a really good job with it.

    My question for you is: What are your future goals for this project (do you plan on expanding on this or do you think you’ll research a different aspect of the everglades? , and what are some policy implications you predict might emerge from the research in this area?

    Wishing you the best in your future endeavors, congrats on getting this far and hope you and your fam are staying safe during this pandemic.


    1. quinn zacharias

      Hi Jenn,

      The review we are writing is currently only qualitative. After this semester, we want to produce quantitative survey’s of the literature to say something like ” x number of studies support a standard of 10 ppb, and y number of studies support a standard that is slightly altered”. Currently, we can’t say that.

      The next policy debate that could be had is probably not what the phosphorus concentrations in the interior everglades should be,. Rather, I think it should be about what phosphorus concentrations can we allow in water that is passing into the Everglades. How low do those need to be? I am also interested in how we can continue to drive phosphorus levels lower. One avenue that I think is really interesting is using activated carbon bed filters (large beds of charcoal) for filtering phosphorus out of the water before it enters into the Everglades. The idea is currently being tested on. They’re calling it “the clean water machine”. I think it is an interesting idea, but there are some questions about feasibility and scaling that might be fun to do research on.